Ascent Communication Technology

400G QSFP-DD SR8 850 nm 100 m

Ascent’s QSFP-DD-LP-01 is a 400 Gb/s Quad Small Form Factor Pluggable-double density (QSFP-DD) optical module designed for short-range optical communication applications. The module is designed to operate over multi-mode fiber systems using a nominal wavelength of 850 nm. The electrical interface uses a 76-pins connector, and the optical interface uses an MPO connector.

• Compliant to QSFP-DD MSA

• Compliant with IEEE 802.3cd

• Supports 400 Gb/s aggregate bit rate

• Up to 53.125 Gbps data rate per channel

• Up to 70 m link length on OM3 and 100 m on OM4

• MPO connector receptacle

• Case temperature range: 0 °C to +70 °C

• Power dissipation < 10 W

• RoHS compliant

Absolute Maximum Ratings

It has to be noted that the operation in excess of any individual absolute maximum ratings might cause permanent damage to this module.

Parameter	Symbol	Min.	Typ.	Max.	Unit	Notes
Storage Temperature	T_S	‑40		+85	°C
Relative Humidity	RH	5		85	%
Power Supply Voltage	V_CC	‑0.4		3.6	V

Recommended Operating Conditions

Recommended operating environment specifies parameters for which the electrical and optical characteristics hold unless otherwise noted.

Parameter	Symbol	Min.	Typ.	Max.	Unit	Notes
Operating Case Temperature	T_C	0	‑	+70	°C
Supply Voltage	V_CC	3.135	3.3	3.465	V
Supply Current	I_CC			2730	mA
Bit Rate	BR		400		Gbps
Data Rate, Each Lane			26.5625		GBd
Data Rate Accuracy		‑100		100	ppm
Fiber Length (OM3 MMF)				70	m
Fiber Length (OM4 MMF)				70	m

Optical Characteristics

Parameter	Symbol	Min	Typ.	Max	Unit	Notes
Transmitter
Modulation Format			PAM4
Signaling Rate, Each Lane (Range)		26.5625 ± 100 ppm			GBd
Center Wavelength	λ₀	840		860	nm
Spectral Width (RMS)	σ			0.6	nm	1
Average Launch Power, Each Lane		‑6		4	dBm
Outer Optical Modulation Amplitude (OMA_outer), Each Lane		‑4.0		3	dBm	2
Launch Power in OMA_outer ‑ TDECQ		‑5.9			dBm
Transmitter and Dispersion Eye Closure (TDECQ), Each Lane	TDECQ			4.9	dBm
Average Launch Power of OFF Transmitter, Each Lane				‑30	dBm
Extinction Ratio, Each Lane	ER	3			dB
Optical Return Loss Tolerance	ORL			12	dB
Receiver
Modulation Format		PAM4
Data Rate, Each Lane		26.5625 ± 100 ppm			GBd
Receiver Wavelength	λ	840		860	nm
Damage Threshold		5			dBm	3
Average Receive Power, Each Lane		‑7.8		4	dBm	4
Receive Power (OMA_outer), Each Lane				3	dBm
Receiver Reflectance	R_R			‑12	dB
Stressed Receiver Sensitivity (OMA_outer), Each Lane	RSENS			‑3	dBm
Receiver Sensitivity (OMA_outer), Each Lane (Max.)	RS = max(‑6.5, SECQ ‑ 7.9)				dB	5
Difference in Launch Power between any Two Lanes (OMA_outer)				4.6	dBm
Conditions of Stressed Receiver Sensitivity Test
Stressed Eye Closure for PAM4 (SECQ), Lane under Test			4.9		dB	6
OMA_outer of Each Aggressor Lane			3		dBm	6

Notes:

1. RMS spectral width is the standard deviation of the spectrum

2. Even if the TDECQ < 1.9 dB, the OMA (min) must exceed this value.

3. The receiver shall be able to tolerate, without damage, continuous exposure to an optical input signal having this average power level on one lane. The receiver does not have to operate correctly at this input power.

4. Average receive power, each lane (min) is informative and not the principal indicator of signal strength. A received power below this value cannot be compliant; however, a value above this does not ensure compliance.

5.Receiver sensitivity is informative and is defined for a transmitter with a value of SECQ.

6. These test conditions are for measuring stressed receiver sensitivity. They are not characteristics of the receiver.

Electrical Characteristics

Parameter	Symbol	Min	Typ.	Max	Unit	Notes
Supply Voltage	V_CC	3.135	3.3	3.465	V
Supply Current	Icc			2730	mA
Transmitter
Input Differential Impedance	Rin		100		Ω	1
Differential Data Input Swing	Vin,pp	400		900	mV
Receiver
Differential Data Output Swing	Vout,pp			900	mV	2

Notes

1. Connected directly to TX data input pins.

2. In to 100 Ω differential termination

Digital Diagnostic Monitoring Information

Parameter	Accuracy	Calibration
Temperature	±3 °C	Internal
Voltage	±3 %	Internal
Bias Current	±10 %	Internal
TX Power	±3 dB	Internal
RX Power	±3 dB	Internal